Just the other day, I wanted to upload the photos which I did took for a work event.

Upon inserting the SD card into my computer, I noticed that a great many of the files (about one quarter) were converted to formats such as .AVA or .BPG or .BP0. This includes some of the photos and ALL of the videos. I did some research and found out that:

.AVA files are used by Photoshop, among others.

.BPG extension´s are so-called 'Borland Project Group' files which bear some relation or other to Delphi. You can read more about this file-type here.

I can tell by the size of the files that the videos were converted both to .BPG and .AVA formats. Same with photos.

The memory card on which these pictures was stored was used to transfer photos twice before I used it in my computer. The first time it was used on the day of the event to transfer photos to a Mac. The second time, I used it on a work PC to transfer the files to the server. This work computer had Photoshop CS5 installed on it.

During the transfer, I browsed through the photos and everything, including the videos, seemed to be working fine. After this second time, i plugged in the card to transfer the photos to my home PC. This is when I received an error message claiming files on the card were corrupt. I then checked the card and saw this multitude of file-types which I have never before seen.

An additional interesting fact: The items in the DCIM folder add up to to about 4.2 gigabytes of data. However, it appears that there is actually 6+ gigabytes of data on the card. There are no other folders though and I cannot see any more files...

The equipment I was using is as follows:

Nikon D300S

MicroSD card with SD Adapter.

I wanted to ask the people here at DPReview if they have ever experienced issues of this kind. Personally, this has never happened to me before and I find it quite disconcerting. I was thinking it might be an issue with the memory card, but why would it work perfectly twice and then suddenly decide to convert files? Then it occurred to me that Adobe Bridge on the work computer might have done something to the photos while trying to index them. But i'm not sure to what extent this can happen...